osmux: Allocate struct osmux_out_handle through API

Until now, the osmux_in_handle was allocated by the client, and passed
to the API to initialize it. This makes it really hard to improve the
implementation without breaking the ABI.

Let's break the ABI now one last time (hopefully) by allocating the
struct through an API. With only this change, the already built users
(osmo-mgw, openbsci, osmo-bts) can still work fine, since there's no
change on the struct osmux_in_handle. However, they will somehow break
next time thestruct is changed until they are ported to the same API
(easy to do).

Change-Id: I752ab031f935f04731bb1a354333f1682a1aa5bd
Related: SYS#5987

TODO-RELEASE

@@ -8,3 +8,4 @@
 # If any interfaces have been removed or changed since the last public release: c:r:0.
 #library	what		description / commit summary line
 libosmo-netif   osmux           new osmux_xfrm_output_* APIs
+libosmo-netif   osmux           new osmux_xfrm_input_* APIs

include/osmocom/netif/osmux.h

@@ -103,8 +103,13 @@ int osmux_snprintf(char *buf, size_t size, struct msgb *msg);
 /* 1500 - sizeof(iphdr) = 20 bytes - sizeof(udphdr) = 8 bytes. */
 #define OSMUX_BATCH_DEFAULT_MAX		1472
 
-void osmux_xfrm_input_init(struct osmux_in_handle *h);
-void osmux_xfrm_input_fini(struct osmux_in_handle *h);
+struct osmux_in_handle *osmux_xfrm_input_alloc(void *ctx);
+void osmux_xfrm_input_init(struct osmux_in_handle *h) OSMO_DEPRECATED("Use osmux_xfrm_input_alloc() instead");
+void osmux_xfrm_input_fini(struct osmux_in_handle *h) OSMO_DEPRECATED("Use talloc_free() instead");
+int osmux_xfrm_input_set_batch_factor(struct osmux_in_handle *h, uint8_t batch_factor);
+void osmux_xfrm_input_set_batch_size(struct osmux_in_handle *h, uint16_t batch_size);
+void osmux_xfrm_input_set_initial_seqnum(struct osmux_in_handle *h, uint8_t osmux_seqnum);
+void osmux_xfrm_input_set_deliver_cb(struct osmux_in_handle *h, void (*deliver_cb)(struct msgb *msg, void *data), void *data);
 
 int osmux_xfrm_input_open_circuit(struct osmux_in_handle *h, int ccid, int dummy);
 void osmux_xfrm_input_close_circuit(struct osmux_in_handle *h, int ccid);

src/osmux_input.c

@@ -587,6 +587,56 @@ int osmux_xfrm_input(struct osmux_in_handle *h, struct msgb *msg, int ccid)
 	return ret;
 }
 
+static int osmux_xfrm_input_talloc_destructor(struct osmux_in_handle *h)
+{
+	struct osmux_batch *batch = (struct osmux_batch *)h->internal_data;
+	struct osmux_circuit *circuit, *next;
+
+	llist_for_each_entry_safe(circuit, next, &batch->circuit_list, head)
+		osmux_batch_del_circuit(batch, circuit);
+
+	osmo_timer_del(&batch->timer);
+	talloc_free(batch);
+	return 0;
+}
+
+/*! \brief Allocate a new osmux in handle (osmux source, tx side)
+ *  \param[in] ctx talloc context to use when allocating the returned struct
+ *  \return Allocated osmux in handle
+ *
+ * This object contains configuration and state to handle a group of circuits (trunk),
+ * receiving RTP packets from the upper layer (API user) and sending batched &
+ * trunked Osmux messages containing all the data of those circuits down the
+ * stack outgoing network Osmux messages.
+ * Returned pointer can be freed with regular talloc_free, all pending messages
+ * in queue and all internal data will be freed. */
+struct osmux_in_handle *osmux_xfrm_input_alloc(void *ctx)
+{
+	struct osmux_in_handle *h;
+
+	h = talloc_zero(ctx, struct osmux_in_handle);
+	OSMO_ASSERT(h);
+
+	struct osmux_batch *batch;
+
+	h->batch_size = OSMUX_BATCH_DEFAULT_MAX;
+
+	batch = talloc_zero(h, struct osmux_batch);
+	OSMO_ASSERT(batch);
+
+	INIT_LLIST_HEAD(&batch->circuit_list);
+	batch->remaining_bytes = h->batch_size;
+	osmo_timer_setup(&batch->timer, osmux_batch_timer_expired, h);
+
+	h->internal_data = (void *)batch;
+
+	LOGP(DLMUX, LOGL_DEBUG, "initialized osmux input converter\n");
+
+	talloc_set_destructor(h, osmux_xfrm_input_talloc_destructor);
+	return h;
+}
+
+/* DEPRECATED: Use osmux_xfrm_input_alloc() instead */
 void osmux_xfrm_input_init(struct osmux_in_handle *h)
 {
 	struct osmux_batch *batch;
@@ -608,6 +658,34 @@ void osmux_xfrm_input_init(struct osmux_in_handle *h)
 	LOGP(DLMUX, LOGL_DEBUG, "initialized osmux input converter\n");
 }
 
+int osmux_xfrm_input_set_batch_factor(struct osmux_in_handle *h, uint8_t batch_factor)
+{
+	if (batch_factor > 8)
+		return -1;
+	h->batch_factor = batch_factor;
+	return 0;
+}
+
+void osmux_xfrm_input_set_batch_size(struct osmux_in_handle *h, uint16_t batch_size)
+{
+	if (batch_size == 0)
+		h->batch_size = OSMUX_BATCH_DEFAULT_MAX;
+	else
+		h->batch_size = batch_size;
+}
+
+void osmux_xfrm_input_set_initial_seqnum(struct osmux_in_handle *h, uint8_t osmux_seqnum)
+{
+	h->osmux_seq = osmux_seqnum;
+}
+
+void osmux_xfrm_input_set_deliver_cb(struct osmux_in_handle *h,
+				     void (*deliver_cb)(struct msgb *msg, void *data), void *data)
+{
+	h->deliver = deliver_cb;
+	h->data = data;
+}
+
 int osmux_xfrm_input_open_circuit(struct osmux_in_handle *h, int ccid,
 				  int dummy)
 {
@@ -656,16 +734,10 @@ void osmux_xfrm_input_close_circuit(struct osmux_in_handle *h, int ccid)
 	osmux_batch_del_circuit(batch, circuit);
 }
 
+/* DEPRECATED: Use talloc_free() instead (will call osmux_xfrm_input_talloc_destructor()) */
 void osmux_xfrm_input_fini(struct osmux_in_handle *h)
 {
-	struct osmux_batch *batch = (struct osmux_batch *)h->internal_data;
-	struct osmux_circuit *circuit, *next;
-
-	llist_for_each_entry_safe(circuit, next, &batch->circuit_list, head)
-		osmux_batch_del_circuit(batch, circuit);
-
-	osmo_timer_del(&batch->timer);
-	talloc_free(batch);
+	(void)osmux_xfrm_input_talloc_destructor(h);
 }
 
 /*! @} */